The invention relates to a process to cool/condition air heated in a process, in particular machine exhaust air which is cooled through heat exchange by means of a cooling medium, whereby a fluid medium is used as the cooling medium.
A number of machines, e.g. textile machines, in particular open-end spinning machines, release process air at high temperature. A large open-end spinning machine with approximately 290 rotors has an installed capacity of approximately 75 kW. Added to this capacity is an illumination capacity of approximately 4 kW in the machine room (spinning room) and a roof load of approximately 6 kW, (in particular sunlight irradiation) depending on the time of the year and the geographic location. From all of this it appears clearly that a very great amount of exhaust heat is produced by each machine. In order to maintain temperature and humidity conditions in the spinning room that are required for smooth yarn production, approximately 85 kW output per machine is fed to the air conditioning plant which cools and conditions the air at a high energy expenditure. The hot process air leaves the process at a temperature of approximately 50.degree. C., i.e. 25.degree. C. above room temperature. In many geographic locations with hot climate, it has been shown that cooling of the hot process air to a lower temperature, i.e. to a lower enthalpy value, is more energy-efficient than to exterior air.
The cooling of process air by means of cooling water flowing through a cooling coil and coming from a cooling tower which is part of the circuit is known, for example, from U.S. Pat. No. 4,857,090. The cooling water which is heated during the cooling process is returned to the cooling tower, is cooled there to a lower temperature and is then again available to cool the hot process air. This known process needs improvement from the point of view of energy efficiency.